Tissue sampling and removal apparatus and method

ABSTRACT

A tissue sampling device ( 10 ) for retrieving one or more tissue samples from a patient is either handheld or mounted to a moveable carriage ( 184 ) and advanced so that the needle tip ( 152 ) is introduced into the patient. The needle tip ( 152 ) is advanced until the tissue receiving basket ( 154 ) reaches the tissue sample target zone ( 190 ). Vacuum pressure is supplied to the basket ( 154 ) via a vacuum tube ( 144 ) so that tissue to be sampled is drawn into the basket ( 154 ). The cutter ( 42 ) is rotated and advanced linearly to cut a tissue sample ( 212 ) which is then retrieved by retracting the needle ( 40 ).

TECHNICAL FIELD

[0001] The present invention relates to tissue sample removal and, moreparticularly, breast tissue biopsy apparatus and procedures.

BACKGROUND OF THE INVENTION

[0002] Various known tissue and biopsy removal apparatus and methodsexist. Known devices include various types of needle coring and moveablecutter devices. Certain of such devices lack effective cutting ability,the ability to retrieve multiple samples, or versatility in terms of usewith a variety of accessories and in a variety of procedures. Forexample, certain tissue removal devices are limited in terms of theirneed to be used only with certain types of tables or imaging equipment.Some tables or imaging equipment are expensive or cumbersome. Sometables or imaging equipment are adapted to fit or be used with one or alimited number of models and manufacture of biopsy or tissue retrievaldevices.

[0003] Some handheld biopsy or tissue retrieval devices exist but lackthe effective cutting and tissue retrieving capabilities of morecomplex, automated devices normally restricted to use with tables andlarger assemblies. Certain handheld devices are limited to single tissuesample retrieval operations and must be fully removed before subsequentsamples can be taken, thus losing the precise location of a priorsample.

OBJECTS OF THE INVENTION

[0004] It is an object of the present invention to provide a tissueremoval device and method that have superior cutting ability, theability to retrieve multiple samples while holding a tissue sample site,and versatility in terms of use with a variety of accessories and in avariety of procedures. It is a further object to provide a tissueremoval device and method that may be used with a carriage and table orthat may be used in a completely handheld fashion.

[0005] These and other objects and advantages that are inherent to thepresent invention are disclosed herein.

SUMMARY OF THE INVENTION

[0006] The present invention is directed to a tissue removal device andmethod that utilizes a device having a housing that may be handheld ormounted to a carriage used with a conventional biopsy table and imagingsystem. The tissue removal device has a non-rotatable needle including avacuum-assisted tissue sample basket and a rotating needle that can beadvance or retracted linearly. A single, re-usable drive cable having adrive gear mounted at its end is attached to a remote drive motor. Thesingle drive cable rotates selectively to actuate cutter rotation,advancement and withdrawal, as well as selective needle displacement toretrieve a severed sample and to re-position the needle.

[0007] In operation the needle is positioned in a tissue target site sothat a vacuum-pressurized basket near the distal end of the needle drawstissue in. The cutter is rotated and advanced past the basket to sever atissue sample held in the basket. The cutter is then held in positionwhile the needle is retracted in order to locate the tissue basket fortissue removal. The sequence can be repeated as needed until a desirednumber of tissue samples are removed. The rotational location ofsubsequent samples can be controlled by rotating the entire devicerelative to the patient.

[0008] The entire device is designed to be detached from the drive cableand discarded.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a schematic, isometric, partial view of a tissue removaldevice according to a first embodiment of the present invention.

[0010]FIG. 2 is a schematic, exploded isometric view of the device shownin FIG. 1.

[0011]FIG. 3 is a schematic, partial isometric view of the device shownin FIG. 1.

[0012] FIGS. 4A-4B are schematic side views of components of the deviceshown in FIG. 1 being operated in a manner according to a preferredembodiment of the present invention method.

[0013]FIG. 5 is a schematic front view of an optional componentaccording to a first embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Structural Components

[0014] Referring to FIGS. 1-5, a preferred embodiment of the presentinvention tissue sampling device is described herein. The device (10)includes a housing (12) shaped in any one of a variety of configurationsthat is easily hand held or mounted for rotation to another structuresuch as the cradle (14) shown in FIG. 1. The housing (12) is preferablygenerally elongated so as to define a longitudinal axis (16)therethrough. The material of the housing (12) may be any one of avariety of materials, including metals or plastics, suitable for usewith medical devices and of sufficient strength and stiffness to performas described herein. Since in the preferred embodiment the entirehousing (12) and its inner components are intended to be disposed afteruse with a single patient, it is desirable that the housing (12)comprise an inexpensive material. The housing (12) of the preferredembodiment is provided with rotational position indicia (18) forlocating the housing (12) in selective rotational positions relative tothe patient or to the cradle (14), as will be described below.

[0015] At the proximal end (20) of the housing (12), a drive cable port(22) and a vacuum port (24) are positioned on the distal end face (25).The drive cable port (22) receives a drive cable end (26) of a drivecable (80) and the vacuum port (24) receives a vacuum conduit (28), thefunction of each being described below.

[0016] The distal end (30) of the housing (12) includes an extension arm(32) and a distal support (34) forming a tissue specimen retrieval zone(36) proximally adjacent to the distal support (34). A radiolucent tube(38) is mounted to the distal end (30) of the housing (12) in a mannerpermitting adjustable extension distally from the housing (12), as willbe described below.

[0017] Extending from the distal end (30) of the housing (12), andpassing through the distal support (34) are a sampling needle (40) and arotational cutter (42). The cutter (42) is mounted within the housing(12) in a manner permitting it to move rotationally and axially relativeto the housing (12). The needle (40) is mounted within the housing (12)in a manner permitting it to move axially relative to the housing (12),but which prevents relative rotation of the needle (40) relative to thehousing (12).

[0018] Referring to the exploded view shown in FIG. 2, the housing (12)comprises a first half (41) and a second half (44), each being adaptedto interfit with the other to form a single, enclosed housing (12). Thecutter (42) comprises an elongated, hollow tube having a distal end (46)with a sharpened edge for cutting tissue, a proximal end (48), and atissue sample retrieval window (50) located near the proximal end (48).The cutter (42) is preferably made of a metal or similar rigid materialthat may be sharpened at the distal end (46) edge for cutting tissue. Afirst cutter gear (52) is connected to the proximal end (48) of thecutter (42) in a fixed relationship to transmit rotational motion to thecutter (42). The first cutter gear (52) may be connected to the cutter(42) by various suitable means including, as shown, a distal extension(54) that can be welded, press-fit or otherwise attached to the cutter(42).

[0019] An internal gear (56) which is mounted inside the housing (12)for rotational movement only transmits rotational motion to the firstcutter gear (52) which, in turn, rotates the cutter (42). The firstcutter gear (52) and the internal gear (56) are sized so that the firstcutter gear (52) is positioned inside the internal gear (56). The numberand ratio of gear teeth may vary according to desired output. The firstcutter gear (52) is adapted to translate longitudinally inside of theinternal gear (56) in order to facilitate advancement or retraction ofthe cutter (42) in the longitudinal direction relative to the housing(12). The internal gear (56) is mounted in the housing (12) in such amanner that the distal end (58) of the internal gear (56) abuts a firststop plate (60) fixed internally in the housing (12). The proximal end(62) of the internal gear (56) abuts the distal end face (64) of thegear case distal end (66) which is mounted inside the housing (12) in anonmoving manner which will be described below.

[0020] Rotational movement of the internal gear (56) which, in turn,drives the first cutter gear (52) and the cutter (42), is caused byrotational motion transmitted directly to it by the second cutter gear(68). The second cutter gear (68) is fixedly mounted directly to thedistal end (70) of a cutter drive shaft (72). Fixedly mounted to theproximal end (74) of the cutter drive shaft (72) is a third cutter gear(76). The third cutter gear (76), when driven, transmits rotationalmotion through the cutter shaft (72) to the second cutter gear (68) and,thus, the internal gear (62), the first cutter gear (52) and, finally,the cutter (42). Rotational motion is imparted on the third cutter gear(76) by the master drive gear (78) which is driven by the drive cable(80) and housed in the cable housing (82) having a cable housing end(84).

[0021] The drive cable (80) is rotationally driven by a conventionalmotor (86) or other drive means located remotely. The drive cable (80)is moved axially relative to the housing (12) by conventional means suchas a solenoid or other type of linear actuator (88). The linear actuator(88) may, for example, include a push-pull piston (90) adapted to engagea disc or collar (92) that is crimped or otherwise fastened to the cable(80). By selectively moving the cable (80) and thus the master drivegear (78), the third cutter gear (76) can be selectively engaged ordisengaged in order to selectively drive or not drive the cutter (42).

[0022] A cutter advance gear (94) is provided and positioned within thehousing (12) in such a manner so that it is simultaneously engaged bythe master drive gear (78) when the master drive gear (78) engages thethird cutter gear (76). The cutter advance gear (94) cooperates withadditional components, as described below, which convert the rotationalmotion of the master drive gear (78) into linear motion in order toextend or retract the cutter (42) in a linear fashion.

[0023] The cutter advance gear (94) is connected to a cutter advanceshaft (96) by a spring clutch (98) which transmits rotational motionfrom the gear (92) to the shaft (96) in order to linearly advance orretract a lead nut (99) along a threaded section (100) of the shaft(96). The lead nut (99) has an extension arm (102) that extends distallythrough the gear case distal end (66) so that the distal end (104) ofthe extension arm (102) abuts the proximal face (106) of the firstcutter gear (52). As the cutter advance shaft (96) is rotated in a firstdirection, the lead nut (99) translates distally, thereby pushing thefirst cutter gear (52) and hence the cutter (42) so that they movedistally relative to the internal gear (56) and the housing (12). Thespring clutch (98) is selected so that it will allow relative slippagebetween the cutter advance shaft (96) and the cutter advance gear (92)if a predetermined axial resistance force is applied to the cutter (42).The cutter (42) will slow or stop moving in the axial direction, whilecontinuing to rotate, until the resistance is diminished or overcome. Anextension flag (108) of the spring clutch (98) and a retaining clip(110) enable it to be connected to the cutter advance gear (92).

[0024] Accordingly, reversing the direction of rotation of the masterdrive gear (78) will, in turn, control the rotational and linearmovement direction of the cutter (42) in accordance with the operationof the device as will be described below. When the rotation of themaster drive gear (78) is directed to cause the cutter advance gear (92)to rotate in a direction that will result in the lead nut (99) movingtoward the proximal direction, a spring (112) biased on its distal end(114) by a second stop plate (116) and on its proximal end (118) by thedistal face (120) of the first cutter gear (52) will push the firstcutter gear (52) and the cutter (42) back in the proximal direction. Therate of movement in this manner will be dictated by the retreat of thelead nut (99) since it abuts the proximal end (106) of the first cuttergear (52).

[0025] Advancement or retraction of the needle (40) in accordance withoperation as described below, is activated by positioning the masterdrive gear (78) in engagement with the needle drive gear (122). Asdescribed above, the master drive gear (78) is moved axially relative tothe housing (12) and, thus, can be selectively engaged with the needledrive gear (122). As shown in FIG. 3, the needle drive gear (122) isoffset from the third cutter gear (76) and the cutter advance gear (94)so that it can be engaged only when the two latter gears are notengaged, and vice-versa. When the master drive gear (78) engages theneedle drive gear (122), rotational motion from the master drive gear(78) is transmitted through the needle drive gear (122) to the needleleadscrew (124) to which the needle drive gear (122) is fixed. Theleadscrew (124) is threaded so that, when rotated, it causes a togglenut (126) having internal threads (128) and positioned thereon totranslate linearly along the leadscrew (124). Depending on the directionof rotation of the master drive gear (78), the toggle nut (126) willadvance distally or retreat proximally along the leadscrew (124). Thetoggle nut (126) has two flags (130, 132) that extend generally radiallyand that are offset ftom each other axially as shown.

[0026] The first flag (130) of the toggle nut (126) is positionedrelative to the needle (40) in order to selectively engage the distalend face (134) of the needle flange (136). The needle flange (136) isfixedly attached to the proximal end (138) of the needle (40). The firstflag (130) selectively engages or disengages the needle flange (136) bybeing rotated into or out or axial alignment with a portion of theneedle flange (136). When positioned for engagement with the flange(136), the first flag (130) will pull the flange (136) and needle (40)in a retracted, proximal direction as the toggle nut (126) movesproximally along the leadscrew (124) as described above.

[0027] The second flag (132) of the toggle nut (126) is positionedrelative to the needle (40) in order to selectively engage the proximalend face (135) of the needle flange (136). The needle flange (136) isfixedly attached to the proximal end (140) of the needle (40). Thesecond flag (132) selectively engages or disengages the needle flange(136) by being rotated into or out or axial alignment with a portion ofthe needle flange (136). When positioned for engagement with the flange(136), the second flag (132) will push the flange (136) and needle (40)in an extended, distal direction as the toggle nut (126) moves distallyalong the leadscrew (124) as described above.

[0028] In addition to being spaced axially with respect to each other,the flags (130, 132) are offset angularly so that the first flag (130),being located distally of the second flag (132), may be positioned foralignment with the flange (136) while the second flag (132) ispositioned out of alignment with the flange (136). This facilitates theoptional firing mode of the needle (40) that will be described below, bykeeping the second flag (132) out of the way of the flange (136) duringfiring.

[0029] The needle (40) and the attached flange (136) are telescopicallyreceived over the distal end (142) of the vacuum tube (144) for relativeaxial movement with respect thereto. The vacuum tube (144) remains fixedwith respect to the housing (12) when the needle (40) is moved axiallyas described above. The proximal end (146) of the vacuum tube (144) isattached to a vacuum conduit (28) that is attached to a remote vacuumpressure source (150) of a conventional type. The needle (40) has asharpened needle tip (152) adapted to penetrate or cut into tissue.Adjacent to the tip (152) is a tissue sample basket (154). Preferably,the sample basket (154) is provided with holes (156) for applyingsuction to a tissue sample received in the basket (154). The suction isprovided through the vacuum tube (144).

[0030] The internal components described above are housed within thehousing (12) and a proximal end cap (158) forms the proximal end (20) ofthe housing. A toggle nut stop (160) is used to limit proximal movementof the toggle nut (126) and, thus, the needle (40). Distal movement ofthe toggle nut (126) and the needle (40) are limited by the proximalface (162) of the gear case distal end (163). The gear case proximal end(164) comprises a plate having series of holes (168, 170, 172, 174). Thegear case (66) is positioned in the housing (12) toward the proximal. Afirst, central hole (168) receives the vacuum tube (144) and needle(40).

[0031] The needle (40) extends through a central hole (176) in thedistal end (162) of the gear case (66) and through a central hole (178)of the distal support (34). A radiolucent slide (180) having a centralhole (182) aligned with the distal support central hole(178) is providedand receives the needle (40) therethrough. The slide (180) is fixed tothe radiolucent tube (38) and enables it to be adjusted relative to thehousing (12) in the axial direction in accordance with operation asdescribed below.

[0032] The four remaining holes (168, 170, 172, 174) rotationallysupport, respectively, the needle drive gear (122), the master drivegear (78), the third cutter gear (76), and the cutter advance gear (94).

Operation

[0033] In operation, the tissue sampling device (10) is used to retrieveone or more tissue samples from a patient. In a biopsy retrievaloperation, for example, it may be desired to take more than one tissuesample from a patient to locate one or more lesions.

[0034] During a tissue retrieval procedure such as a breast biopsyprocedure, a patient is positioned on or next to a commerciallyavailable biopsy table or other positioning and imaging apparatus. Usingconventional imaging technology, such as ultrasound, a physician locatesa desired target area for tissue sample retrieval.

[0035] The device (10) may either be held in hand by a physician or itmay be mounted to a cradle (14) which is mounted to a moveable carriage(184) as shown in FIG. 1. The carriage (184) is part of an imaging tableor other commercially known positioning device. The device (10) hasbearing grooves (186) designed to cooperate with the cradle (14) to holdthe device (10) within the cradle (14) in a manner permitting rotationalmovement with little friction.

[0036] The initial step to obtaining a tissue sample requiresintroducing the needle tip (152) into and through the skin of thepatient. The needle tip (152) may be advanced into and through the skinin one of two ways. A first way is to merely push the device forward byhand, using only manual force. The physician may monitor position duringsuch introduction of the needle tip (152) using ultrasound imaging.Another way to advance the needle tip (152) into and through the skin isto advance a mechanical carriage (184) which holds the device (10) andthus the needle (152) relative therewith. Using imaging means orpredetermined coordinates associated with carriage position, the needletip (152) can be advance to a target zone.

[0037] After introduction of the needle tip (152) into and through theskin, the needle tip (152) is advanced further by either of the meansdescribed in the preceding paragraph until the needle tip (152) isadjacent to the tissue sample target zone (190) as shown in FIG. 4A.Next, the needle tip (152) is advanced by either means so that thetissue sample receiving basket (154) is positioned within the targetzone (190) as shown in FIG. 4B. Alternatively, the needle tip (152) maybe advanced into the target zone (190) by the optional firing mode.

[0038] In the firing mode, the tip (152) is advanced relative to thehousing (12) by a predetermined distance in a rapid fire manner so as toensure cutting and penetration into a tissue region, rather than pushingthe tissue out of the way of the needle tip (152). To facilitate rapidfiring, a modular firing mechanism (192) having a spring-loaded firinghammer (194) is positioned with the hammer (194) in the firing port(196, FIG. 1) of the housing (12). The hammer (194) lines up proximallyto the needle flange (136) so that when the firing mechanism (192) isfired by pulling its trigger (198), the hammer (194) pushes the flange(136) and needle tip (152) rapidly in the distal direction. It order toexecute this firing mode, it is necessary that the flags (130, 132) arepositioned so that the first flag (130) is positioned for alignment withthe flange (136) while the second flag (132) is positioned out ofalignment with the flange (136), as described above. This keeps thesecond flag (132) out of the way of the flange (136) during firing. Thedevice (10) is preferably shipped in its original, unused state so thatthe flags (130, 132) are in the alignment described immediately above.If necessary, the position of the flags (130, 132) is controlled byrotating the leadscrew (124) in one direction or the other, as thetoggle nut (126) engages the leadscrew (124) with enough friction tocause it to rotate with the leadscrew (124) for a limited rotationaldistance until it makes contact on either side and then the leadscrew(124) rotates relative to the toggle nut (126) to cause it to advancelinearly along the leadscrew (124). Rotation of the leadscrew (124) maybe caused by activating an electronic switch (200), which may be mountedon the housing (12) or remotely, to selectively activate abidirectional, remote rotational motor (86). The motor (86) rotates thedrive cable (80). As described above, the drive cable (80) is movedaxially relative to the housing (12) by conventional means such as asolenoid or other type of linear actuator (88), which can be activatedby an electronic switch (204) located on the housing (12) or remotely.

[0039] After the tissue sample receiving basket (154) is positionedwithin the target zone (190) as shown in FIG. 4B, the cutter (42) ismoved back away from the needle tip (154) by mechanical componentsdescribed above in order to expose the basket (154) to the tissue to besampled as shown in FIG. 4C. The step of moving the cutter (42) may beinitiated by activating an electronic switch (206) located on thehousing (12) or located remotely. Once the basket (154) is exposed tothe tissue sample target zone (190), suction may be applied through theholes (156) via the vacuum tube (144) and vacuum source (150) asdescribed above. The vacuum pressure may be initiated by an electronicswitch (208) located on the housing (12) or remotely. Shortly aftervacuum pressure is activated, and tissue is drawn into the basket (154),the cutter (42) may be rotated and advanced linearly by mechanical meansas described above until it reaches the position shown in FIG. 4D. Thesequence of activating the vacuum and moving the cutter (42) may beinitiated by a single electronic switch (210) located on the housing(12) or remotely.

[0040] After the cutter (42) advances fully past the basket (154), asshown in FIG. 4D, a tissue sample will have been cut and captured in thebasket (154). The cutter (42), now in a distally extended position, isstopped to hold the sample site and the needle (40) is retracted so thatthe basket (154) is positioned in the tissue specimen retrieval zone(36) as shown in FIG. 4E for removal of the tissue sample (212). Thetissue sample (212) may be grasped or removed from the basket (154) byforceps or other known means.

[0041] If a subsequent sample is desired, the needle (40) is advanced byactivating an electronic switch (214) which is located on the housing(12) or remotely which, in turn, activates the mechanical components asdescribed above for linear advancement of the needle (40) using theleadscrew (124) and toggle nut (126). The needle tip (152) is advanceddistally of the cutter (42) as shown in FIG. 4B. The device (10) canthen be adjusted linearly or rotationally relative to the patient andthe tissue target zone (190). The next sequence of retrieving a tissuesample may be initiated by moving the cutter (42) back away from theneedle tip (152) in order to expose the basket (154). The vacuum,cutting and tissue sequences as described above are repeated to obtainanother sample. The above described procedure can be repeated as manytimes as needed to obtain a desired number of samples.

[0042] Upon completion of removal of a desired number of tissue samples,the master drive gear (78) and drive cable (80) are detached from thedevice (10) so that the remainder of components of the device (10) canbe discarded. The vacuum conduit (148) is removed from the vacuum source(150) and discarded along with the device (10). The drive cable (80) canbe attached to a new device of the same type as the device (10)described herein and another vacuum conduit (148) can be attachedbetween the device (10) and the vacuum source (150) for subsequent usewith another patient.

[0043] If it is desired to reduce the length of the tissue area beingsampled, the slide (180) fixed to the radiolucent tube (38) can beextended distally with respect to the housing (12) to a predetermineddistance so as to partially block the sample basket (154) when theneedle (40) is in an extended position. Because the tube (38) and slide(180) are radiolucent, neither will interfere with the ability to viewthe surrounding site during a procedure.

[0044] While the preferred embodiments of the invention have beendisclosed and described herein, it is understood that variation andmodification can be made without departing from the scope of the presentinvention claimed.

What is claimed is: 1) A tissue removal device for selectively removingone or more tissue portions from a medical patient, said devicecomprising a housing; a piercing member for piercing tissue of saidpatient; a tissue receiving section of said piercing member forreceiving a portion of said tissue; a cutting member for selectivelysevering said portion of tissue while it is held in said receivingsection; and a single drive cable operatively attached at one end tosaid housing and at another end to remote drive means for moving saidcutter causing it to sever said portion of tissue and for selectivelymoving said piercing member relative to said housing.
 2. A deviceaccording to claim 1, further comprising a master drive gear attached tosaid single drive cable, said master drive gear being adapted toselectively and operatively engage a drive gear associated with each ofsaid piercing member and said cutting member in order to transmit motionfrom said remote drive means to said piercing member and to said cutter.3. A device according to claim 3, wherein said remote drive meanscomprise a single, rotational motor adapted to rotate in two directions.4. A tissue removal device for selectively removing one or more tissueportions from a medical patient, said device comprising a disposbleportion including a housing; a piercing member for piercing tissue ofsaid patient; a tissue receiving section of said piercing member forreceiving a portion of said tissue; a cutting member for selectivelysevering said portion of tissue while it is held in said receivingsection; and a re-usable portion including a single drive cableoperatively attached at one end to said housing and at another end toremote drive means for moving said cutter causing it to sever saidportion of tissue and for selectively moving said piercing memberrelative to said housing.
 5. A method of selectively removing one ormore tissue portions from a medical patient, said method comprisingproviding a piercing member adapted to pierce tissue of said medicalpatient such that a tip of said piercing member and a tissue receivingsection of said piercing member are positioned within a tissue targetzone; activating a single remote drive motor for causing a cuttingmember to move relative to said piercing member such that a portion oftissue in close proximity to said tissue receiving section is severed bysaid cutting member; and activating said drive motor for causing saidpiercing member to be withdrawn from said patient in order to removesaid portion of severed tissue from said tissue receiving section.
 6. Amethod according to claim 5, further comprising detaching said piercingmember and said cutting member from said drive motor and disposing ofsaid piercing member and said cutting member.